1. Field of the Invention
The invention relates to a bandsaw joint assembly for connecting together end portions of a band saw to form a loop, without requiring conventional welding.
2. Prior Art
Bandsaw apparatus have been used for many years and normally include a pair of spaced co-planar wheels carrying an endless loop of bandsaw. The saw has a longitudinal axis disposed between spaced parallel marginal edges of the saw, and at least one marginal edge has saw teeth, although commonly both edges are provided with saw teeth. The saw itself is usually fabricated from a toothed strip of metal which is cut to the required length, and adjacent end portions are then welded together, commonly using a butt welding process. Any irregularities at the weld itself are usually ground away to provide a relatively smooth joint. The heat of the welding process necessarily changes the temper of the saw material adjacent the weld, thus adversely affecting its wear and toughness characteristics. Also, the joint itself is rarely perfect and usually causes an undesirable "click" as it passes over the wheels carrying the saw for each revolution of the saw itself. It is difficult for a skilled welder to produce a joint in the saw which does not adversely affect the sawing performance at the saw joint.
There have been various attempts to reduce the difficulties of connecting together ends of bandsaws using a non-welding process as follows. U.S. Pat. Nos. 161,263 (Newhall) and 230,934 (Gale and Wright) both disclose cold bandsaw connections which require precision forming of adjacent end portions of the saw to permit the end portions to overlap each other to form the joint. Parts of the overlapping end portions have been thinned to one half of the original saw thickness to maintain normal thickness of the saw, but this weakens the joint. U.S. Pat. No. 361,536 (Miller) discloses a cold joint for adjacent ends of a bandsaw which resembles a conventional "dovetail" wood joint. While this does not require overlapping, it would require considerable forming skills. Applicant considers that all three joints shown in the above patents would present considerable difficulties when the saw joint passes over a normal size wheel mounting the saw. There have been various attempts to provide joints between adjacent sectors of circular saws, and portions of manual crosscut saws, but most of these result in relatively complex connections, requiring high precision joints and various fastening means which would be difficult to incorporate in the relatively thin band saw material used by hobbyists or small machine shops.